The present invention relates to meter reading, and, in particular, remotely reading groups of meters using a bi-directional communication system and protocol.
Utility companies are taking advantage of modern technology to reduce costs and increase efficiency in meter reading applications using wireless technology to remotely gather information from large groups of meters. Traditionally, utility meters, such as electric, water and natural gas, were manually read by utility workers visiting each meter location. Current technology allows meters to be remotely accessed from a central location through wire or wireless communication links. To further increase ease of reading and meter installation, these meters are battery powered and operate to gather parameter measurements for the respective types of meters, and various other information, and then communicate this information to a portable or other remotely situated meter reading device.
In order to keep maintenance low and operating efficiency high, it is desirable to have meters which can operate for an extended period of time without requiring maintenance, battery replacement and the like. Maintenance requirements are generally reduced by increasing battery capacity and reducing power consumption. As a result, the meters generally cycle between low-power sleep modes, to conserve energy, and full-power awake modes, when any combination of meter reading, information gathering, information processing and data transmission may occur.
In operation, the meters periodically awaken from the sleep mode to gather information, such as meter parameter readings, and to check meter status. When the meter is awake, the parameter readings and meter status information may be wirelessly transmitted to the meter reading device and relayed on to a network or utility for processing the information. Additionally, information may be sent from the meter reader to the meter for various reasons, including setting or resetting meter values and storing operating information.
In these applications, many meters of many types may be located within range of the meter reading device. There is a need for a meter and communication protocol capable of providing bi-directional communications to a remote meter reader while avoiding interference from other meters as well as other radio frequency transmissions within the communication range of the meter reading device.
Furthermore, remote interrogation of meters may be performed by different personnel providing different services. For example, certain utility personnel may take meter readings while other personnel may need to configure parameters. Meter manufacturers may also need access to reconfigure software or provide service. In many cases, the different people having access to the meter should have varying levels of access to meter information and the ability to modify meter parameters and settings. Thus, there is a need for a remote meter reading system capable of providing varying levels of access to the people and devices capable of communicating with the meter.
The present invention provides a protocol allowing communication to and from a remote, utility meter with a meter reader capable of communicating with different types of meters using different levels of security for accessing select parameters. Accordingly, one aspect of the present invention relates to a protocol for utility meter interrogation including providing: a) a synchronization string, b) a basic command for indicating the presence or absence of an extended command, c) identification indicia, d) message length indicia for indicating an amount of data included in the message, e) message type indicia indicating utility meter and message type, f) an extended command corresponding to the message type indicia, and g) any data necessary for the command.
The protocol further includes assembling a transmission sequence to include the synchronization string followed by the basic command followed by the identification indicia and, if an extended command is present, followed by the message length indicia followed by the message type indicia followed by the extended command followed by any necessary data, transmitting the transmission sequence from an interrogator of a meter reader and receiving the transmission sequence at the select utility meter.
Preferably, a basic command is included having a first state indicating an extended command will be included in the message and, alternatively, a second state indicating an extended command will not be included in the message. Preferably, only one state is included in each command. Typically, the identification indicia is the serial number for the select utility meter and the message length indicia indicates an amount of information, such as the number of bytes, following the transmission sequence. The message type indicia preferably indicates whether the message is configured to read information from the select utility meter or alternatively to write information to the select utility meter, in addition to indicating the type of utility meter being interrogated. The utility meter type typically includes gas, electric, water or other utility meters.
Another aspect of the present invention provides a protocol for utility meter interrogation having a data write portion including: i) assembling a-password transmission sequence having a synchronization string and a message including identification indicia for a select utility meter and a password to activate a select data access level within the select utility meter; ii) wirelessly transmitting the password transmission sequence a first time to at least one utility meter including the select utility meter; iii) wirelessly transmitting the password transmission sequence a second time to the select utility meter following the first transmission to confirm the password transmission sequence; iv) assembling a command transmission sequence having the synchronization string and a message including the identification indicia and a write command configured to cause the select utility meter to store data in a memory location of the select utility meter corresponding to the data access level activated with the password; v) wirelessly transmitting the command sequence to the select utility meter following the second transmission; and vi) wirelessly transmitting the command sequence a second time to the select utility meter following the third transmission to confirm the command transmission sequence. The protocol may alternatively include a data read portion including: i) assembling a read transmission sequence having a synchronization string and a message including identification indicia for a select utility meter and a data command defining a parameter to be read from the select utility meter; ii) transmitting the read transmission sequence; and iii) receiving data transmitted from the select utility meter in response to transmitting the read transmission sequence.
The command transmission sequence is preferably transmitted within a predetermined period of the password transmission sequences wherein the select utility meter deactivates activation of the select data access level after the predetermined period expires. The predetermined period is preferably 10 seconds and may start upon activation of the data access level. The utility meters will preferably include a plurality of data access levels associated with multiple passwords, wherein each data access level is associated with memory locations for holding data.
Yet another aspect of the present invention provides a utility meter having a remote communication interface for communicating with an interrogation device. The device includes a metering device for measuring utility parameters and an output providing measurement indicia to a control system in memory. Communication electronics are associated with the control system and adapted to transmit received information to and from the meter reader interrogation device. The memory includes a plurality of partitions with passwords associated with each partition.
The control system is adapted to communicate with the interrogation device via the communication electronics using a select protocol to transmit information stored in the memory and store information transmitted from the interrogation device in the partitions. The control system also requires receipt of one of the associated passwords from the interrogation device to store data in one of the corresponding partitions. Preferably, the meter memory includes three partitions representing memory locations having increasing levels of security. Each partition includes a unique password for access to a corresponding partition.
Preferably, the protocol includes receiving data for storing data in a partition by: i) receiving a password transmission sequence including the synchronization string followed by a basic command followed by identification indicia followed by a message length indicia followed by a message type indicia followed by an extended command followed by the password; ii) receiving the password transmission sequence a second time; iii) receiving a data transmission sequence including the synchronization string followed by a basic command followed by identification indicia followed by a message length indicia followed by a message type indicia followed by an extended command followed by the data for storing in the partition; and iv) receiving the data transmission sequence a second time.
The control system is preferably adapted to allow access to the partition associated with the password after receiving the password transmission a second time and write data to the partition after receiving the data password a second time. Typically, access to the partition only lasts a predetermined period of time after receiving the password transmission sequence the second time.
Still another aspect of the present invention provides an interrogation device assembling the various transmission sequences to the various meters according to the protocol described above. The interrogation device includes a control system and communication electronics adapted to transmit and receive information to and from a remote communication unit according to the select protocol in order to interrogate various types of utility meters and access various levels of memory if select passwords are available or known by the interrogation device operator.
These and other aspects of the present invention will become apparent to those skilled in the art after reading the following description of the preferred embodiments when considered with the drawings.